# Heat Effects and Calorimetry

Topics: Heat, Temperature, Thermodynamics Pages: 4 (1101 words) Published: December 8, 2010
Introduction

The first law of thermodynamics states that the energy of the universe is constant. Heat is transferred when the atoms of one material vibrate and collide with the atoms of another material, thus transferring energy. For this reason, heats always travel from hot to cold objects and two objects will reach an equilibrium temperature.

Materials and Methods

1. Oven7. Test Tube
2. Pasco Temperature Probe8. Stopper
3. Scale9. Calorimeter
4. Samples of Metals10. HCl solution
5. Water11. NaOH solution
6. Beaker

The sample metals are put to boil. In the first trial, the investigators use sample metal #2. Pour an amount of distilled water in the beaker and measure. After obtaining the mass/weight of the distilled water, record its temperature using the temperature probe. The distilled water’s temperature (room temperature) is the initial temperature (Ti) of the water. Note that the initial temperature and the final temperature will be used to get the “change of temperature” of the water. Take out the metal from the oven and quickly put it in the beaker with water while simultaneously taking its temperature using the temperature probe. In this process, heat transfer is taking place. While the computer is recording the measurement, changes in the temperature is evident. The water temperature goes up from its initial room temperature to a higher temperature until it reaches its equilibrium. Equilibrium is when the temperature is steady without any change. Weigh the metal and record the data then calculate.

The heat of solution reaction is similar to that is present when a hot metal is put into water. There is an exchange of heat between the reaction mixture and the solvent, water. The heat flow associated with the reaction mixture is also equal to the enthalpy change. One of the simplest reactions that can be studied in solution occurs when a solid is dissolved in water.

Same with the neutralization of HCl...